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R H Hinton

Publications and source records attributed to R H Hinton.

70 records · Page 4Linked to original sources
PubMed1974

Heterogeneous distribution of enzymes among plasma-membrane fragments sedimenting with the microsomal fraction of rat liver.

Plasma-membrane fragments recovered in the microsomal fraction of rat liver homogenates were shown to be heterogeneous in density. It was demonstrated that 5'-nucleotidase, the most commonly used plasma-membrane marker, is concentrated in the lightest subfraction. Two of the published procedures for the isolation of plasma-membrane fragments from the microsomal fraction (Touster et al., 1970; Hinton et al., 1971) are shown to give products which are not representative of all the plasma-membrane fragments of microsomal size, and it is argued that a third procedure (House & Weidemann, 1970) is likely to give a similar product.

Adenine Nucleotides↗
PubMed1973

Alkaline ribonuclease and phosphodiesterase activity in rat liver plasma membranes.

The ribonuclease and phosphodiesterase activities of rat liver plasma membranes, purified from the crude nuclear fraction by centrifugation in an A-XII zonal rotor and flotation, were examined and compared. The plasma membrane is responsible for between 65 and 90% of the phosphodiesterase activity of the cell and between 25 and 30% of the particulate ribonuclease activity measured at pH8.7 in the presence of 7.5mm-MgCl(2). Both enzymes were most active between pH8.5 and 8.9. Close to the pH optimum, both enzymes were more active in Tris buffer than in Bicine or glycine buffer. Both plasma-membrane phosphodiesterase and ribonuclease were strongly activated by Mg(2+), there being at least a 12-fold difference between the activity in the presence of Mg(2+) and of EDTA. There is, however, a difference in the response of the enzymes to Mg(2+) and EDTA in that the phosphodiesterase is fully activated by 1.0mm-MgCl(2) and fully inhibited by 1.0mm-EDTA, whereas the ribonuclease requires 7.5mm-MgCl(2) for full activation and 5mm-EDTA for full inhibition. Density-gradient centrifugation has indicated that on solubilization in Triton X-100 most of the ribonuclease activity is released into a small fragment of the same size as that containing the phosphodiesterase activity. The relationship between the two activities is discussed in view of these results.

Animals↗
PubMedDate not supplied

The experiences of families with a relative in the intensive care unit.

OBJECTIVE: To describe the experiences of families with a relative in the intensive care unit (ICU). DESIGN: Retrospective, descriptive, and qualitative. SETTING: The surgical-trauma ICU in a midwestern university-affiliated tertiary medical center. PARTICIPANTS: Eighteen women and 2 men with relatives in a surgical trauma ICU. OUTCOME MEASURES: Focus group and individual unstructured interviews. RESULTS: A group interpretive process was used to code, categorize, and identify themes found in the transcribed interviews. Four categories of experiences were identified: hovering, information seeking, tracking, and the garnering of resources. Hovering is an initial sense of confusion, stress, and uncertainty. Information seeking is a tactic used both to move out of the hovering state and to identify the patient's progress. Tracking is the process of observing, analyzing, and evaluating patient care and status and the family's own satisfaction with the environment and with care givers. The garnering of resources is the act of acquiring what family members perceive as needed for themselves or their relative. CONCLUSIONS: Families experience a sense of uncertainty that is eventually resolved by seeking information and resources. Health care professionals can minimize the stress associated with hospitalization of relatives in the ICU by anticipating and addressing the family's needs for information and resources.

Adaptation, Psychological↗
PubMedDate not supplied

Enhanced arsenite-induced hepatic morphological and biochemical changes in phenobarbital-pretreated rats.

Changes in liver morphology and biochemistry have been assessed 16 hr after a sc injection of sodium arsenite [As(III), 75 mumol/kg] to control and phenobarbital (PB)-pretreated (80 mg/kg, ip daily for 3 days) adult male Wistar rats. As(III) administration to PB-pretreated rats [PB + As(III)] caused hydropic degeneration, total loss of glycogen, necrosis in some centrilobular zones, and an increase in lipid vacuoles around the periportal area. Electron microscopy showed an increased number of vacuoles and autophagosomes containing organelle-like material. There was a 30% decrease in total hepatic cytochrome P-450 (CYP450). O-dealkylation of ethoxy- and pentoxyresorufin and N-demethylation of benzphetamine decreased to 42, 32, and 30% of control values, respectively. 5-Aminolevulinic acid dehydrase decreased 25% from controls, and metal chelatase activities decreased to 25% of the PB-treated group. Injection of As(III) alone resulted in a mild increase in lipid-containing vacuoles around the periportal zone, a moderate loss of glycogen in midzonal areas, and, by electron microscopy, a dilatation of the bile canaliculi and an increase of the number of myelin-like structures. CYP450 content and the O-dealkylation of ethoxy- and pentoxyresorufin and N-demethylation of benzphetamine all decreased between 30 and 50%. These results demonstrate the greater susceptibility of the liver to injury following PB with compounds not requiring metabolic activation. The metabolic basis of these changes are unclear but may result from an increased demand for metabolic energy due to PB induction and decreased adenosine triphosphate synthesis caused by arsenic.

Animals↗